Tremendous gains in manufacturing productivity and quality have been realized by the application of modem automation techniques to production processes. Most of the earliest advancements involved automating fabrication processes, such as numerically controlled tooling machines. Typically, the work piece was manually installed into a fixture, or “fixtured,” the computer-controlled process performed, and then the work piece was manually removed from the fixture. Subsequent advancements improved the material handling aspects of the process, such as with the proliferation of robotics. Today, it's not unusual to see all aspects of the fabrication process from raw material to packaging performed by flexible manufacturing cells connected by material transfer devices.
Flexible manufacturing approaches are typically able to process different types of parts so that one cell can be used in the manufacture of different products. For example, a packaging cell might be able to receive different size containers for use in packaging different sizes or types of products. This flexibility furthermore aids the development of new and different products because the likelihood of consequential costly modifications and downtime to the manufacturing process are greatly diminished.
Some types of work pieces are characteristically more challenging to handle with automated processes. A thin and easily deformable sheet of material, for example, presents special challenges as compared to a rigid member when picking and placing such an object. For this reason, it is not unusual to see human assistance necessary in operations requiring singulating sheet material work pieces, such as lightweight thermoformed clamshell type packages. Such a requirement for manual intervention is all the more certain where different types or sizes of clamshell packages are processed, and where the packages are received and used in a stacked arrangement. The penalty associated with relying on manual intervention can be very significant.
It has been determined that singulating a work piece such as this can be automatically done reliably by gripping a medial portion thereof, unstacking the work piece, and then supporting the distal ends of the unstacked work piece. It is to these improvements and others as exemplified by the description and appended claims that embodiments of the present invention are directed.